Method of forming a fitting



Feb, 27, 1934. as. CORNELL, JR 1,948,564

METHOD OF FORMING A FITTING Filed April 16, 1932 2/ IINVENTOR a? IATTORNEY Patented Feb. 27, 1934 UNITED STATES PATENT OFFICE My presentinvention relates to pipe fittings and more particularly to an improvedmethod of making sheet metal pipe fittings.

In my patent for pipe fittings and method of making the same, granted tome under date of March 15, 1932, and bearing Patent No. 1,850,049, Ihave described and claimed an improved pipe fitting constructed of sheetmetal, preferably copper and the longitudinal passage of such pipefitting is provided with a seam on the side opposed from the lateral,such seam being formed by folding up the juxtaposed edges of the metalsheet and enclosing such folded juxtaposed edges in a channel shapedmember, and

afterwards compressing the folded edges and the channel shaped member soas to cause practically a cold flow or weld of the metal and producethereby a fluid-tight joint. Due to the difficulty of manipulating thefittings during the process of making the fluid-tight joint or seam andbecause of the inequality in the stresses existing in the various piecesof metal being worked upon, it was often found extremely difficult,though possible, to obtain a satisfactory fluid-tight joint, but thecost of such joint was relatively high in comparison with the total costof the manufacture of the fitting itself.

With a view of obtaining a satisfactory fluidtight joint in fittings ofthis character which will 00 not add materially to the cost ofmanufacture of the fittings, I have devised the present method of makinga seam or joint in fittings made of sheet metal, and in carrying out myinvention, I have utilized, as in the fitting formed according to mypatent above referred to, the folded parallel edges of the so-calledskirting of the material to form the longitudinal passage through thefitting and have enclosed such folded parallel edges in a channel shapedmemher, but before applying pressure to consolidate the channel member,the folded parallel edges and the adjoining portions of the skirtinginto a unitary mass, I have associated in the space formed by theparallel folded edges and the outer face of the channel member, a rod orstrip of relatively soft material, that is, material that is relativelysoft as compared to the material of which the fitting and channel arecomposed. After such rod or strip is in position, I subject the joint topressure, to consolidate the channel member, the rod ,or strip ofrelatively soft material the adjoining, parallel folded edges of theskirting of the material and the adjoining portions of the skirtingmaterials into a unitary mass by subjecting the same to pressure. I haveskirting enclosed in the channel member such found that the relativelysoft material of which the rod or strip is composed, is readilyincorporated in the adjoining faces of the channel member and the foldedover parallel strips so as to form practically a single unitary piece ofmetal at the joint and therefore, form a joint that is fluid-tight underthe range of pressure to which the fitting may be subjected in use. Suchjoint is formed by moderate pressure being applied to the various partsand while I have extensively practiced this methed of forming a joint,the number of failures of the joint is extremely low as compared withthe heretofore practiced method of forming such joint.

The object of my invention, therefore, is an improved method of formingseams or joints in the manufacture of sheet metal pipe fittings, and theresulting fitting and joint thereof.

In the accompanying drawing illustrating the various steps by myinvention,

Fig. 1 is aside elevation, partly in section, of a- T pipe fitting towhich myinvention is applied;

Fig. 2 is an end elevation of Fig. 1;

Fig. 3 is an enlarged end section of a portion of the longitudinalmember of a fitting, such as a T, showing the ends of the skirting ofsuch longitudinal member folded over and arranged in position withrespect to each other, prior to enclosing the same in a channel member;35

Fig. 4 is a perspective view of a channel member utilized for enclosingthe folded over ends of the skirting shown in Fig. 3;

Fig. 5 is a perspective view of a section of rod or strip of metalutilized in the process of formingthe joint;

Fig. 6 is an end elevation of a portion of the longitudinal member of apipe fitting such as is shown in Fig. 1, showing the folded ends of the,

5 as shown in Fig. 4 and with a length of rod or strip of relativelysoft metal in position and prior to the application ofpressure to form afluid-tight joint, and v Fig. 7 is an end elevation of the parts shownin Fig. 6 in position in a'structure for applying pressure thereto, andafter pressure has been applied to form a fluid-tight joint.

Referringto the drawing, 10 designates the longitudinal member of a pipefitting such as a T from one side of which extends a lateral member 11.Both the longitudinal member and the lateral member are formed of asingle sheet of material and the lower portion of the longitudinalmember, that is. the portion opposite the lateral extension 11, isformed of two skirts, 12, 13, the edges of which are outwardly foldedover to be enclosed by an exterior channel memher 1 1 to form anexterior seam designated generally by the numeral 15 in Fig. 1, suchexterior seam extending along the length of the longitudinal member 10.

The skirts 12, 13, during the formation of the joint have their adjacentedges folded over as indicated at 16 and 1'], respectively, in Fig. 3,the portions 16, 17, lying at an angle to each other, as shown,extending divergently of one another. The angle formed by the foldedpor- 'tions 16, 17, is substantially similar and equal to the angleformed by the members 18, 19, the exterior of channel member 20, and inFig. 6, such channel member 20 is shown in position on the folded overexterior portions 16, 17.

In Fig. 5 is shown, in perspective, a rod 21 of relatively soft metal,that is, a metal that is relatively soft as compared with the metal ofeither of the elements 12, 13, 16, 17, or 20. In Figs. 5 and 6, themember 21 is shown as a red but obviously I may utilize a strip of metalof any cross-sectional area and the circular rod 21 as shown is merelyused for convenience and does not limit the novelty of my improvedmethod.

After the rod 21 is placed in position, as shown in Fig. 6, thelongitudinal member having the skirts 12, 13, is placed on a cylindricalmandrel 22 in a press (not shown) having clamping members 23, arrangedsubstantially as shown, such members 23 defining a passage extendinglongitudinally of the member 10 and providing thereby a guideway for aplunger 24, the under face of the plunger 24 being contoured to form theunder face or side of the resulting joint substantially concentric withthe outer diameter of the longitudinal member 10. The mandrel 22 ismaintained substantially in position while pressure is ordinarilyapplied to the plunger 24 whereupon the assembly shown in Fig. 6gradually assumes the form shown in Fig. '7, and as the pressurecontinues to be applied the material constituting the rod or strip 21 iscaused to fiow to fill up the substantially triangular space between thefolded over portions 16 and 1'? and it has been found that the materialof the rod or strip 21 is actually cold flowed or welded into thematerial of the folded over portions 16 and 17 and of the channel member21, and this to such an extent that the line of demarkation between suchvarious elements is obliterated and there results therefore afiuid-tight joint. In such pressure operation, as appears from acomparison of Fig. 6 with Fig. 7, the angles of the respectiveexteriorly folded over portions 16, 17, relative to the skirt portions12, 13, are gradually decreased, until the exterior folded over portion16, 17, respectively, are brought home to their final positionsindicated in Fig. 7, in accompaniment with the compression and cold flowof the relatively softer material of the rod 21 into the materials ofthe folded over portions 16, 1'7, and of the channel member 21.

As is illustrated in Fig. '7, the face of the plunger 24 is providedwith a projection, see

24a, which coincides with and extends substantially centrally andlongitudinally of the channel member 14, thereby effecting an indenting14a of the channel member at its central longitudinal portion, thusenhancing the resistance of the channel member against displacement. Itwill be observed that such indenting 14a is formed was es in juxtaposedrelation to the meeting faces of the rounded ends 1211', 13a of therespective juxtaposed edge portions of the eventually cylindri cal body12, 13.

Additionally, such indenting 14a, under pressure exerted by theprojection 24a of the plunger 24, forces the flow under pressure of thematerial 21 toward and within the jointure of the meeting faces 12a, 13asimultaneously as the infolded edges 18, 19 of the channel member 14 andthe folded edge portions 16, 17 of the eventually cylindrical body arebrought into mutually locking relationship with one another, whereby ahighly effective seal is attained at the joint by the combinationaleffects of the pressure of the meeting faces 12a, 13a, of the edgeportions of the eventually cylindrical body against one another, thepressure of the interposed material 21, sustained in position by theinterlocking channel member 1%, reinforced by its indenting 14a.

My improved fluid-tight joint has been described in connection with asheet metal pipe fitting only for the reason that such joint wasdeveloped in connection with pipe fittings, but it is obvious that myinvention is applicable to a variety of uses, such as the joining ofseparate sheets of metal together by a joint of this character, andtherefore I am not to be limited with regard to my claim to a structuresuitable only for use in forming a fluid-tight joint in pipe fittings.

Preferably, the element of relatively soft material is formed of amaterial or materials which do not produce any electrolytic effect withthe material of the fitting or parts thereof in use, and also ofmaterial or materials which are not corroded chemically or otherwise bythe fluid with which the fitting or other joined member is used.

Whereas I have described my invention by specific reference toformations thereof, it will be understood that many changes andmodifications may be made without departing from the spirit of theinvention.

I claim.

The improved method of forming a fitting having a substantiallycylindrical hollow body provided with opposite end openings and alateral opening communicating with the interior of the hollow body anddisposed intermediate the body end openings, which comprises formingfrom a single sheet of ductile metal the body and the body end portionsand the lateral end portion integrally with one another, the edges ofthe sheet being brought into juxtaposition, bending the juxtaposed edgeportions outwardly to form flanges, interconnecting such resultingoutward fianges by an inversely bent connecting strip, interposingrelatively soft material between the flanges and the body portion of theinterconnecting strip and locking and sealing the joint between theoutward flanges and the interconnecting strip by applying pressurejointly to the interconnecting strip, the body flanges and theinterposed relatively soft material while indenting the body of theinterconnecting strip centrally and longitudinally to displace therelatively soft material toward and within the joint between the meetingfaces of the body flanges and between the body flanges of theinterconnecting strip under sufficient pressure as to effect a cold fiowinterlocking between the stated parts.

EDWARD S. CORNELL, JR.

